Pump



w. F. THOMPSON l PUMP Filed Dec. 4, 1943 v,axe L\\ Dec. 25, l1945.

Patented Dec. 25, 1945 UNITED STATES .PATENT GFFICE PUMP Willis F. Thompson, Portland, Maine, assignor to The Alden Speares Sons Co., Cambridge, Mass., a corporation of Massachusetts Application December 4, 1943, Serial No. 512,860

7 Claims. (Cl. 222-318) The invention relates to a pump especially 4 and serves a valvular purpose later to be re'- adapted for the delivery of corrosive liquids from ferred to. containers, or carboys. The top end 9 of the internal coupling 5 pro- The object of the invention is to provide a vides a valve seat for an inwardly o-pening :ball pump of the specied character which will invalve I0 which is caged within the chamber I I herently function to safeguard the operator whatof the coupling. ever may be the degree of internal pressure de- Fitting within the top end of the tubular casveloped within the pump. For eiecting the ing I is a tubular head piece I2 which has an Dumping Operation, the pump is provided with a upward extension from the top end of the casing. piston operated by a piston rod. The piston 10 A packing I3 lls the joint between the bottom operates within a cylinder, with the piston rod, end portion of the head piece and the adjacent which actuates the piston, extending outside `the top end portion of the casing, thus sealing this cylinder through a joint open to the atmosphere joint from the chamber I5 of the casing. This 'and through which joint the piston rod slides. packing is formed of any suitable more or less It is the especial object of my invention to preelastic material unaffected by acid, and which vent the escape of liquid through this joint by will makeatight joint. relieving the joint of all pressure which might Surmounting the top end of the casing and effect an escape of 'the liquid through it however slidable upon the head piece I2 is a cap I6, to fast the pump may be operated, and this withthe top end II of which is threaded the top end out aiecting the proper action of the pump. of a piston rod I8, the cap'forming a hand grip A further object of the invention is to improve by which the piston rod is reciprocated. The upon the pump shown and described in my United cap is of substantially the same diameter as the States Patent No. 2,360,085; this especially from casing I and the top end of the casing forms a manufacturing standpoint by providing a pump a stop for limiting the down thrust of the piston of more simple construction and having less parts rod through engagement of the bottom edge of than the pump shown in my application. the cap with the top edge of the casing. TheA The invention can best be seen and understood piston rod ts slidably within the head piece. by reference tothe drawing in which The joint between it and the head piece is closed Fig. 1 is a vertical cross section of the pump at the bottom end of the head piece by a valve embodying my invention, 80 I9 with which the piston rod has sliding engage- Fig. 2 is a section on line 2 2 of Fig. l; and ment. This valve is preferably formed of the Fig. 3 is a section on the line 3-3 of Fig. 1. same packing material as fills the joint I3, this Referring to the drawing I represents an outmaterial in fact being brought down to wrap side tubular casing or cylinder, the top end of around the bottom end portion of the head piece, which is closed in a manner later to be described. which end portion is preferably made tapered, At its bottom end the tubular casing ts tightly and thence continued beyond the bottom end of within the top end of a hollow stopper 2. This the head piece onto the side of the piston rod, stopper is tapered and 'lits snugly within the thusfclosing the joint between the piston rod and open top end or mouth of a container or carboy the head piece and sealing it from the chamber 3, and provides the means by which the pump is 40 I5 of the casing. The piston rod is a tubular attached to and makes closed connection with rod with chambered interior 20 closed at its top the container during .the operation of the pump. end, where the rod is made solid, and ai', 'fS

`Connecting with the interior to the bottom end bottom end closed by a plug-2I which fits withof the casing and protruding therefrom through in the bottom end of the piston rod. the hollow of the stopper is a short pipe 4. This The piston comprises ari/internal sleeve 22 slidpipe is secured by an internal tubular coupling able within the casing I andwith which co- 5 to a pipe extension 6 of suiiicient length to operates both an annular head 23, on the lower extend to the bottom of the container when the end of the piston rod, and pins 24 laterally propump has been attached to it. Connection bejecting from the piston rod. These pins lie above tween the pipe 5 and the interior to the bottom 50 the sleeve 22; the head below it. The head iS end of the casing is secured by a packing I of of lesser diameter than the interior diameter of some more or less elastic material unaffected by the casing. Both the head and the combined acid. This packing is provided with a thin tubu pins are of such diametrical extension and lar web or apron 8 which extends for a short length, respectively, that they will engage the distance downwardly over the side of the pipe sleeve for moving it within the casing when the piston is reciprocated. The head is spaced from the pins a distance longer than the length of the sleeve so that when the piston rod is raised its annular head will be brought into engagement with the bottom end of the sleeve and make closed engagement therewith. Accordingly as the piston rod is drawn up the sleeve will be moved upwardly within the casing by the drawing engagement of the head. The combined head and sleeve will then operate as a piston and induce a partial vacuum in the chamber 25 of the casing below the piston, causing liquid in the container or carboy to enter this chamber by way of the pipe connection leading into the container 3, the valve I then being drawn-open, and iilling the chamber of the casing up to the point of the ascending piston.

During this operation undisplaced liquid contained in the chamber I5 of the casing above the ascending piston will be forced to outlet through a spout 26 which is connected to the upper end portion of the casing below the joints closed by the packing I3, and the valve I9, respectively.

Upon the return of the piston through lowering of the piston rod all upward iiow of liquid from the container will cease. The valve I0 will resume its normal closed position. The head 23 will separate from the sleeve thereby forming a communication through the piston so that liquid in the chamber I5 of the casing lying below the piston may enter that portion of the chamber of the casing lying above the piston. The pins 24 will be brought into engagement with the sleeve moving it downwardly through the chamber of the casing to the limit of the liquid so displaced Will ow out of the chamber of the casing through the spout. Thus the pump is a double acting pump causing flow of liquid from the spout during both the upward and downward strokes of the 4piston.

During these operations of the piston, especially if the piston rod is rapidly reciprocated for operating the pump, considerable liquid pressure will be formed in the chamber of the casing'with possibility that liquid might escape through the joint between the piston rod and the head piece I2 within which the piston rod is slidable even though this joint is closed by the valve I9, and the pressure acting to eifect a better closure of this valve for sealing the joint. It is to safeguard the pump against any such escape of liquid that further provision is made that no such pressure will ever be obtained within the chamber I5 of the casing as will produce an escape of liquid by the joint through which the piston rod is passing.

To this end an opening or openings A2l! are formed in the piston rod aording communication from outof the chamber I5 of the casing into the interior 20 of the piston rod, These openings are located adjacent the bottom en d of the piston rod. Contained within the interior of the piston rod and leading out of this chamber through the plug which closes the bottom end of the piston rod is a .drainage tube 29.. This tube extends downwardly through the bottom end portion yof .the casing with extension into the pipe 4 where it connects with a tube section 30. This tube section extends laterally through the pipe 4 at a point above the chamber II for the ball valve I0, so as not to interfere with the free opening of this valve. The opposite ends of the tube section 30 are in open communication with the interior of the container so that liquid entering the interior of the piston rod will escape through the drainage tube and pipe section 30 `and be returned to the container. In order to prevent a too free escape of liquid from the chamber of the casing back to the container the ends of the pipe section 30 are preferably closed by the web 8 previously referred to, which functions as a valve for normally closing these ends. This web or valve, however, offers but slight resistance to the escape of liquid through the ends of the pipe section 30, the valve being opened by the liquid upon the development of slight pressure within the pump.

The drainage tube 29 is of such length that the open top end 3l of the tube will occupy a position slightly below the entrance to the spout 26. Accordingly, upon the cessation of the pumping operation, liquid in the casing will escape back through the drainage tube, and the drop of the liquid in the casing below the entrance to the spout will clear the spout of any `liquid remaining in it, and thereby prevent drip. In some cases if the piston has been rapidly reciprocated the interior of the piston rod may have become lled with liquid up to a point above the opening into the drainage tube. If this condition prevails at the end of-a pumping operation then, before there can be any drop in the liquid in the casing for eliminating drip from the spout, the liquid within the interior of the piston rod must have been lowered to the level of the opening into the drainage tube. This etect, however, will be quickly obtained owing to the fact that when the liquid in the interior of the piston rod is forced to rise above the opening to the drainage tube air will be compressed 'within the top of the interior of the piston rod. This compressed air will, at the end of any pumping operation, tend to quickly lower the liquid in the interior of the piston `rod to the level of the opening to the drainage tube and clear this tube, thus enabling such gravitational fiow back from the chamber of the casing as will prevent drip from the spout. In order that this result may be obtained it is at least desirable, if not necessary, that the web or valve 8 should be arranged to normally have some opening, as small opening 32 for the free passage of liquid from the end or ends of the tube section 30. In any event, the drainage opening should not be so large as to interfere with a proper functional operation of the pump.

I claim: .1. In a pump through the operation of which liquid may be drawn from a container source the combination comprising a chambered casing with delivery outlet, means whereby liquid may be drawn into the casing from the source comprising a hollow piston and piston rod, the interior of the rod .communicating with the chamber of the casing, 4means whereby excess liquid within the rod will be directed back to .the source including. .a drainage tube in open communication with the interior of the rod and connections .leading from the tube to the source, and .means for controlling the passage o f liquid through the tube and connections back to the source whereby liquid from the casing will be permitted to pass through the tube and connections back to .the source upon the development of pressure Within the casing for relieving such pressure.

2. In a pump through the operation of which liquid may be drawn from a container source the combination comprising a chambered casing with delivery outlet, means whereby liquid may be drawn into the casing from the source comprising a hollow piston and piston rod, the interior of the rod communicating with the chamber oi the casing, means whereby excess liquid within the rod will be directed back to the source including a drainage tube and connections leading from the tube to the source, said tube being provided with an opening to the interior of the rod which opening is located below the delivery outlet from the casing whereby liquid remaining in the casing and delivery outlet after the pumping operation will drain through the tube and connections and drip from the delivery outlet be thereby obviated, and means for controlling the passage of liquid through the tube back to the source whereby drainage will be elfected as aforesaid without preventing a proper functional operation of the pump.

3. In a pump through the operation of which liquid may be drawn from a container source the combination comprising a chambered casing with delivery outlet, means whereby liquid may be drawn into the casing from the source coinprising a hollow piston and piston rod, the interior of the rod communicating with the chamber of the casing, means whereby excess liquid within the rod will be directed back to the source including a drainage tube in open communication with the interior of the rod and connections leading from the tube to the source, and means displaceable to an open position by pressure generated within the casing for restricting the passage of liquid through the tube and connections back to the source.

4. In a pump through the operation of which liquid may be drawn from a container source the combination comprising a chambered casing with delivery outlet, means whereby liquid will be drawn into the casing from the source comprising a hollow piston and piston rod, the interior of the rod communicating with the chamber of the casing, means whereby excess liquid within the rod will be directed back to the source including a drainage tube and connections lead- Y ing from the tube to the source, said tube being provided with an opening to the interior of the rod which opening is located below the delivery outlet from the casing whereby liquid remaining in the casing and delivery outlet after the pumping operation will drain through the tube and connections and drip from said delivery outlet be thereby obviated, and means for controlling the passage of liquid through the tube and connections back to the source whereby drainage will be effected as aforesaid without preventing a proper functional operation of the pump and the passage of liquid to the source be augmented upon the development of pressure within the casing.

5. In a pump through the operation of which liquid may be drawn from a container source the combination comprising a chambered casing with delivery outlet, means wherebyA liquid may be drawn into the casing from the source comprising a. hollow piston and piston rod, the interior of the rod communicating with the chamber of the casing, means whereby excess liquid within the rod will be directed back to the source including a drainage tube and connections leading from the tube to the source, said tube being provided with an opening to the interior of the rod which opening is located below the delivery outlet from the casing whereby liquid remaining in the casing and delivery outlet after the pumping operation will drain through the tube and connections and drip from the delivery outlet be thereby obviated, and displaceable means for controlling the passage oi liquid through the tube and connections back to the source whereby drainage will be effected as aforesaid Without preventing a proper functional operation of the pump and the passage of liquid to the source be augmented upon the development of pressure within the casing.

6. In a pump through the operation of which liquid may be drawn from a container source the combination comprising a chambered casing with delivery outlet, means whereby liquid may be drawn into the casing from the sourcecomprising a hollow piston and piston rod, the interior or the rod communicating with the chamber of the casing, means whereby excess liquid within the rod will be directed back to the source including -a drainage tube and connections leading from the tube to the source, said tube being provided with an opening to the interior of the rod which opening is located below the delivery outlet from the casing whereby liquid remaining in the casing and delivery outlet after the pumping operation will drain through the tube and connections and drip from the delivery outlet be thereby obviated, and a valve displaceable to an open position by pressure generated within the casing for restricting the passage of liquid through the tube and connections back to the source, the valve having an opening in it allowing the drainage of liquid as aforesaid without preventing a proper functional operation of the Pump.

'7. In a pump through the operation of which liquid may be drawn from a container source the combination comprising a chambered casing with delivery outlet, means whereby liquid may be drawn into the casing from the source comprising a hollow piston and piston rod, the interior of the rod communicating with the chamber of the casing, means whereby excess liquid within the rod will be directed back to the source including a. drainage tube and connections leading from the tube to the source, the tube being located within the rod and in open communication with the interior thereof, and means for controlling the passage of liquid through the tube and connections back to the source whereby liquid from the casing will be penmitted to pass through the tube and connections back to the source upon the development of pressure within the casing for relieving such pressure.

WILLIS F. THOMPSON. 

